A light emitting device is a kind of semiconductor devices that convert electrical energy into light, and is in the spotlight as a next generation light source replacing a conventional fluorescent lamp, an incandescent lamp, etc.
Since a light emitting diode generates light by using the semiconductor devices, the light emitting diode consumes very low power as compared with incandescent lamps which generate light by heating tungsten, or fluorescent lamps which generate light by colliding ultraviolet rays generated through high pressure discharge on a phosphor.
In addition, since the light emitting diode generates light using potential gaps of the semiconductor devices, the light emitting diode has long life span, fast response characteristics, and eco-friendly characteristics compared to conventional light sources.
Accordingly, various studies have been performed to replace the conventional light sources with the light emitting diode, and the light emitting diode is increasingly used as light sources for lighting devices used indoors and outdoors such as various lamps, liquid crystal display devices, electronic signboards, street lamps, etc.